Development and evaluation of a new high-TOF-resolution all-digital brain PET system

Area of Science:

• Medical Imaging
• Nuclear Medicine
• Neuroscience

Background:

• Time-of-flight (TOF) capability and high sensitivity are crucial for brain PET imaging.
• These features enhance contrast and signal-to-noise ratio (SNR), enabling precise localization of brain activity.
• Existing systems require advancements for more detailed functional and kinetic brain studies.

Purpose of the Study:

• To introduce and evaluate a novel brain PET system with enhanced TOF performance and sensitivity.
• To assess the system's capabilities in phantom and human brain imaging studies.
• To demonstrate the potential for precise kinetic brain PET imaging and quantitative diagnostics.

Main Methods:

• Development of a brain PET system with a 320 mm transverse and 255 mm axial field-of-view.
• Utilized lutetium-yttrium oxyorthosilicate crystals and SiPM detectors with multi-voltage threshold (MVT) technology for signal digitization.
• Evaluated system performance using phantoms (mini-Derenzo, image quality) and conducted time-dynamic human brain imaging.

Main Results:

• Achieved a TOF resolution of 249 ps, sensitivity of 22.1 cps/kBq, and NECR peak of 150.9 kcps.
• Demonstrated spatial resolution capability down to 2.0 mm rods and significant reduction in background variability with TOF reconstruction.
• Observed a 1.7-fold increase in SNR (from 27.07 to 46.05) in human brain imaging; time-dynamic imaging revealed distinct uptake patterns and flow dynamics.

Conclusions:

• The developed TOF-enabled brain PET system integrates excellent TOF capability with high sensitivity and count rate performance.
• The MVT digital sampling technique contributes to the system's efficiency.
• This system advances the potential for precise kinetic brain PET imaging, paving the way for new quantitative predictive brain diagnostics.